Capsule gauge



March 23, 1954 L. s. WILLIAMS 2,672,695

CAPSULE GAUGE Filed May 12, 1951 2 Sheets-Sheet 1 3 m k I g g, a 00 j LAWRENCE 's'. WILLIAMS ttornegl L. s. WILLIAMS CAPSULE GAUGE March 23, 1954 2 Sheets-Sheet 2 Filed May 12, 1951 I Zhwentor LAWRENCE S. WILLIAMS E if Gttornega Patented Mar. 23, 1954 2,672,695

UNITED. STATES PATENT OFFICE CAPSULE GAUGE Lawrence S. Williams, Toledo, Ohio, assignor to ToledoScale Company, Toledo; Ohio, a corporation of New Jersey Application May 12, 1951, Serial No. 225,935 Claims. (01; 33479) p y 2 This invention relates to measuring-equipment the ends of the metallic band. The invention and in particular to gauges for the measurement further includes the provision of a plurality of of generally circular members the areas of which hook rigidly attached to and spaced along the must be precisely known. In the gau ing band and adapted to position the band on the machined circular or cylindrical "pieces during 5 part being measured.-- v

manufacture it is usually customary to measure Preferred embodiments of the invention are their diameters; I This is a satisfactory methodillustrated in the accompanying drawings.

for, most types of partsbecausa they-are sufIi-n' In the drawings: ciently rigid to maintain their shapes and because Figure I is a plan view of the improved au inmost instances, particularly where parts must positioned to measure the-smaller or inner cirbe fitted together, the diameter of the part is cumference of an annular member.

a--critical dimension. In the manufacture of Figure II is a plan view of a similar gauge hydraulic-scalesyand in particular those elements adapted to measure the outer" circumference of called capsules that supportthe load receiver agenerally circularmember.

and converteor translate the load forces into Figure III is a side elevation partly in section, hydraulic pressure-it .isnecessary not only that of a hydraulic capsule showing the partsto -be the; diameters be quite accurate but, more impormeasured.

tant, it is necessary that-the areas of the cap- Figure IV is a smallvertical section showing" sule'members be'verypreciselycontrolled. It is one of the gauge positioning members.

notmecessarythahthe capsule: parts be precisely Figure V is a'perspective viewof'the tension-ins circularrsince they may be-slightly elliptical and and indicating mechanism of thegauge shown still have the correctrar'eas Suclr-partsrmay'be in Figure II.

gaugedby measuringtheir circumferences'which, Fi ure VI is a similar view of the tensioning ionthesmall amounts of- .eccentricity that may and indicating'mechanism shown inFigur'e I. be expected, are precisely related to the areas of Figure VII is a detailed section of the upper the members being measured. I portion of the tensioning member.

The principal: object or this inventionis to Figure VIII is a detailed view showing the provide gauges adapted to acburately'measure the cooperation ofthe-fixtures-on the ends of the inside or outsider-"oi cumferences of hydraulic gauge band and the drive for the indicator. scale' parts.'--- M. w

Figure IX is a detailed view of one of the fixt v l t i t 1 i Another object of the :inventionis' to'provide tures employed on'the' end of the band and Figgauges for measiring the-circumference of -a" ure X isan' enlarged isometric view illustrating member which gauges have I? substantially f the the method of attaching the positioning elements 't same-temperature"coefiicientof expansion' as the to the band. part: beingimeasurdand" which have suffici'efitly These specific" figures lo'w"heatlcapacity that they reach" the tempera'- description are intended merely to illustrate the and the accompanying ture of'thep'artsliein'g measured'during a measinvention but not to impose limit'ations on its" tiring operation: i I t further" obj ect of the: invntion V a circumference-indicating gauge having' means m the" smaller circumference'of'an annular mem= is toprovide' Figure I illustrates a gauge adapted to measure" for'ap'plyin'g'a predetermined force'tothe gauge ber. Such a gaugecomprises a thin metallic member conforming to 'tlievcircumferenceof the' band I which is supported in place against the Dart"beihg'measuredr i a.

Another object of the invention is to provide' engagements of hooks'or gu'ides"2 with afiat locating elements on the gauge for accurately surfaee'o'f an annular capsule member 3. The

inner cylindrical surface of the member by the positioning the gauge" in"measuringrelation tb ends of theband' l are'secured in "a gauge! hav= the capsuleelement'beingmeasured apparent from thefollowing' description of"pre-* the member 3. feri'ed fo'rin's of'theinvention'. l

ing' an indicator 5,: cooperating chart ore specificobjects and 'advantages are for indicatin variations in the circumference of FigureI I shows a similar'g'augefor measuring Accordin'g to'the inventiongauges for 'm'ea'sur the buternircumferenCe of a generally circular ing'generallycircularcapsule elements-are concapsule member I. This gauge comprises a thin struct'edof a thin' l netallic band the length'of" metalliobaind 8 h:aVi'ng a plurality of locating which is slightly shorter than thecircumfei'ence elements or hooks 9 spaced around 'itsjperiphery of thepartbeing measuredand theendsof which and an indicating mechanism" l0, includin an are fitted into a fixture comprising relatively indicator II that cooperateswith a chart H, for

movable resiliently connected members for mainindicating variationsin the circumference of the tainiiiglforce the'ba'nd and'a pointer iorindimember being measured.

Carne ie-irritations: iii engthor the'ga between Ganges employing flexible metallic bands such as the bands I and 8 are particularly well adapted for measuring machined parts, the areas of which must be precise but which may be slightly elliptical. An illustration of such a device is a capsule for hydraulic scales, such as illustrated in Figure III. Such a capsule comprises a base member I3 having an upper fiat surfac corresponding to the member I shown being measured in Figure II. The capsule also includes an annular member I4 which is bolted or otherwise rigidly secured to the under surface of the marginal area of an upper capsule member I5. The space between the upper surface of the base I3 and the upper capsule plat I5 i filled with a hydraulic fluid which is confined by a rubber liner I6 and II. The lower liner IT has a bead I8 that fits into a gap left between the rim at the top of the base I3 and the rim of the annular member I4. The head I8 of the liner I1 is supported against stretching by a basket I9 of a generally semi-torroidal shape comprising a great plurality of narrow, closely spaced metallic bands that are anchored to reinforcing strips 23 and 2 I. The outer, juxtaposed areas of the liners I3 and I! are securely clamped together to form fluid tight joints when the annular member I4 is bolted or otherwise secured to the upper capsule plate I5. The hydraulic pressur developed within the capsul is communicated through a pipe 22 to pressure measuring equipment that indicates the load on the scale.

In order that the pressure developed in the capsule be precisely related to the load on the capsule it is necessary that the effective area of the capsule be precisely known. The effective area of such a capsule is the average of a first cross-sectional area lying within the cylindrical outer surface of the base member I3 and a second area lying within th inner cylindrical surface of the annular member I4. These cylindrical surfaces support and define the horizontal position of the thin metallic members or bands supporting the bead of the capsule liner H. The precise dimensions that must be known to determine the eifective area of th capsule are thus the circumferences of the base l3 at the point of support of the basket I9 and of the annular member I4 at the point where it supports the basket I 9. The improved gauges are designed to measure the circumference of the members at these points to determine their effective areas.

The improved gauges are shown in considerable detail in Figures V through IX inclusive, thus in Figure V, which shows the gauge attached to measure the circumference of the plate I, the ends of the thin metallic band 8 are rigidly fastened in fixtures 23 and 24, which fixtures are in turn attached to handle members 25 and26. The handles 25 and 26, like the legs of a bow compass, are hingedly connected together at their upper ends by a heavy C-shaped spring 21.

The gauge indicator assembly 4 is similarly constructed in that it comprises fixtures 28 and 29 rigidly attached to the ends of th thin metallic band I. The fixtures, in turn, are attached to handles 30 and 3| which at their p er ends are connected together by a h nge in lud n a heavy C-shaoed spring 32. The details of the hinge connections are shown in Figure VII. It will be noted th t the hand e po t ons 25 an 33 are al e an that the cooperating handle portions 25 and 3| are also ali e so t t one set may be nterchanged. for the other. Pefe r ng a ain to Fi ure II. each of t e n le p tions 33 and 3 has a tr ns erse n tch 33 to receive a be eled end of the C-shaped spring 32 and each, on its ber 3 being measured.

surface adjacent the other, has a pair of transverse semicylindrical grooves to selectively accommodate a hinge pin 34. If the hinge pin is in the position shown in Figure VII the lower ends of the handle portions 30 and 3| are urged apart so as to separate the ends of the band I thus causing the band to expand against the inner circumference of the annular member 3. If the hinge pin 34 is located in the other of the pair of transverse grooves it is within the c-shaped spring 32 so that the spring urges the ends of the handle portions 30 and 3I toward each other, the condition required for the gauge illustrated in Figures II and V.

When the internally expanding ing placed in position to measure an insid circumference the operator merely pinches the handle portions 30 and 3I together against the action of the spring 32 thus shrinking the band I enough to allow it to drop into plac in the member to be measured.

The externally contracting gauge I0, shown in Figures II and V, differs in that it is fitted with finger portions 35 and 36 so that the operator in grasping and pinching th finger portions together expands the thin metallic band 8 so that it may be dropped into place over the periphery of the plate 1.

Referring now to Figure VIII each of the gauges includes a base plate 31 that is attached to the under surface of the fixture 24 or 29. The other fixtures 23 or 28 are free of the base plate. The base plate 31 also carries a chart portion 38 on an end remote from the fixtures 23 and 24 and an indicator 39, pivotally supported on pivot pins extending through partially overlapping bifurcated ends 40 and M of the fixtures 23 and 24, cooperates with the chart 38 to indicate the relative position of the fixtures 23 and 24 with respect to each other and thus the deviation of the circumference of the band 8 from a standard circumference.

A short helical spring 42 (Figure V) connected between the indicator 39 and an upwardly extending tab 43 of the base 31 urges the indicator in a direction th t assists the spring 21 in drawing the fi tures 23 and 24 toward each other to tight n the band 8. A similar spring 44 (Figure VI) forces the fixtures 28 and 29 apart so as to aid the spring 32 in enlarging the band I to fit the inner circumference of the annular mem- In each case the short helical spring urges the indicator to the A" portion of the chart which in the outs de gauge I It indicates an undersize piece and in the in ide gauge mechan sm 4 representing an oversize gauge 4 is bepiece. Pieces of correct si"e cause the indicator to stop opposite the center portion of the chart while an o ersize plate I or an undersi e annular member 3 ca ses the corre pon ing indicator to m e to a position opposite the 3" portion of the chart 38.

Since the effective area of the capsule is the average of the area of the. plate and of the annular member it follows that a correct effective area may be obta ned bv matchin an oversize plate with an undersize r n or vice versa. If the ca sule pa ts are marked accor ing to t e indicator readin s one may assemb e acc rate capsules by employin "A plates with A" rin s s nce the average area is then correct even thou h one member was oversize and the other under-size.

The bands I and 8 have beveled edges ad acent the ends asseen in Fig re IX to fit into dovetail slots in the fixtures'23 and 24 and are secured by use of a cement and by mechanical pressure exerted by a screw extending through a hole 45 and threaded through the lower section of the fixture. The fixture itself is split in a horizontal direction throughout the greater portion of its length so that when the screw is tightened the band 8 is rigidly clamped in place. This illustrates a practical way of attaching the band and providing a structure in which the band is flush with the surface of the fixture so that it may be placed in direct contact with the object being measured.

Likewise the locating members 9 are each provided with a dovetail slot 40 that fit over beveled portions 47 (Figure X) of the thin metallic band 8. The edge of the band 8 has a notch 48 cut in one side so that the locating member 9 may be fitted onto the band 8 by hooking the lower beveled surface of the band into the dovetail notch 46 and then bringing the upper edge of the dovetail notch #36 through the band notch 38 and then sliding the band 8 longitudinally until the beveled edges 41 of the band 8 are engaged in the dovetail slot 46. A cement may be applied to hold the parts in the assembled position.

The thin metallic bands I or 8, when the gauges are in use, are subjected to tension or compression stress produced by C-shaped springs 21 or 32 and the indicating springs 42 or 44 so that they closely fit the members being measured. To avoid errors arising from diiferences in temperature, the thin metallic bands I and B are made of a material having the same or substantially the sam temperature ccefiicient of expansion as the parts being measured. Furthermore the construction of the indicator portions and the locating members 2 or 9 are such that the band is placed in accurate and intimate contact with the article being measured. This intimate contact in cooperation with the extremely low heat capacity of the thin metallic band allows the band to rapidly come to the same temperature as the part being measured. Since the parts reach substantially the same temperature and have generally equal temperature coeflicients of expansion, errors due to changes of dimension with temperature are minimized if not completely eliminated.

Various modifications in details of construction of the parts may be made without departing from the spirit and scope of the invention.

Having described the invention. I claim:

1. In a-gauge for measuring the circumference of generally circular bodies the cross-sectional areas of which must be precisely known, in combination, a thin metallic band having a gap, a fitting attached to each end of the band adjacent the gap, a pointer fulcrumed on one of said fittings and pivotally connected to the other, a graduated member fixed to the fitting on which the indicator is fulcrumed, said member cooperating with said pointer to indicate changes in the length of the gap, and spring means connecting said fittings for holding the fittings in alignment and urging them in a predetermined direction parallel to the adjacent portions of the metallic band.

2. In a gauge for measuring the circumference of generally circular metallic bodies the cross-sectional areas of which must be precisely known, in combination, a thin metallic band having the same temperature coeificient of expansion as the body to be measured whereby changes in the area of the body due to temperature changes will be compensated for by a proportional change in the length of the band when said band is in contact with said body, said band having a gap, a fitting on each end of the band adjacent the gap, a pointer fulcrumed on one fitting and pnvotally connected to the other for indicating the length oi the spring means for holding the fittings in alignment and urging one in a predetermined direction with respect to the other, and means for locating the band on the body to be measured.

3. In a gauge for measuring the circumference of generally circular metallic bodies the crosssectional areas of which must be precisely known.

measured, said band having a gap, fitting on each end of the band adjacent the gap, handle means connecting the fittings, said band being flush with the surface of the fittings, and a plurality of hooks attached to the band, said band being recessed into the hooks to be flush with with the body to be measured.

4. In a gauge for measuring the circumference of generally circular bodies the cross-sectional areas of which must be precisely known, in commeans for indicating variations in the length of the gap.

5. In a gauge for measuring the circumference of generally circular metallic bodies the crossthan the circumference to be measured, a fitting on each end of the band adjacent the gap, handle with the surface thereof whereby said band may be placed in intimate contact with the body to be measured.

LAWRENCE S. WILLIAMS. References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 144,606 Fenton Nov. 18, 1873 380,836 Warfield Apr. 10, 1888 783,562 Zimmerman Feb. 28, 1905 1,334,955 Johansson et al. Mar. 30, 1920 1,419,428 Ulrich June 13, 1922 1,958,864 Richardson May 15, 1934 2,500,313 Harrington Mar. 14, 1950 FOREIGN PATENTS Number Country Date 593,808 Germany Mar. 5, 1934 

